Functional GI Disorders

Introduction

Functional gastrointestinal disorders such as Irritable Bowel Syndrome are the most common form of digestive disease in seen our society. Our research primarily focuses on the role of the intestinal microbiota in the expression of functional disorders. Based on our experience in studying post-infectious IBS in the Walkerton population as well as with pre-clinical models of post-infectious IBS, current work addresses interactions between the microbiota and host intestinal and immunological functions that include epithelial integrity, enteric neural function and gut motility in conventional, gnotobiotic and germ-free mice. In addition, in light of the high prevalence of psychiatric comorbidity in IBS, our research examines the impact of the gut microbiota on by-directional brain interactions and on brain chemistry and behavior in our murine models. Our strategies include comparisons of gut and brain function between germ-free and specific pathogen free mice, and mice treated with probiotic bacteria. Our models also include the study of intestinal physiology, immune activation and brain function/behavior in ex-germ-free mice colonized with microbiota from IBS patients or healthy controls. Evaluation of mechanisms underlying microbiota-induced changes in host function include the characterization of immunological and neurological responses, analysis of the shared metabolome, host gene expression studies as well as characterization of the microbiota using molecular and culture-based approaches. This strategy is supported by the availability of bio-samples from a large registry of well-phenotyped IBS patients that also enables bench-to bedside extrapolation of our preclinical research into patients attending our GI clinics.